UPACMIC project
UPACMIC LIFE12 ENV/FI/000592 (Utilisation of by-products and alternative construction materials in new mine construction) is an EU LIFE funded project aiming to study the utilization possibilities of alternative construction materials in mining facilities. The project tests different waste and by-product materials in pilot construction as such and as refining components together with local moraines and mine enrichment sands. The project started in 2013 and will be continued until the year 2020. The coordinator of the project is Ramboll Finland and the associated beneficiaries are Suomen Maastorakentajat Oy and Fortum Environmental Construction Oy. The project is supported by Ministry of the Environment and Yara Finland.
Project activities
Structures made of waste fractions can impact on the quality and amount of the seeping water, which further impacts the water amount and quality seeping from the enrichment sand basin. For example, pH of fly ash is very alkaline which can impact the seeping water pH level.
By adjusting the pH level, the solubility of certain metallic detrimental elements to the seeping water can be decreased. The amount of water seeping through enrichment sand basin (cover structures) and the amount of uncontrolled waters to the environment (bottom structures) can be impacted by material’s water permeability. Ao. bentonite rich foundry sand and fibre clay can have a significant impact on the water permeability.
Large scale construction activities are ongoing in Nivala and Orivesi. In Pyhäsalmi, preliminary field tests were done in spring 2016. Fibre clay will be utilized in cover structure in Nivala where the Hitura mine is going to be closed. The intention is to use energy production ash and gypsum (not mixed) combined with moraine as a reactive layer in the cover structure instead of bare moraine. In Orivesi Mine fibre clay will be utilized in the bottom structure which is based on the preliminary studies made in the UPACMIC project.
Alternative materials
Characteristics of different ashes vary between their reactivity, compactibility and refining value. These characteristics impact significantly on the properties of different structure solutions. The objective of the material studies is to find a right solution to a right purpose by utilizing local materials. This will allow efficient savings in the use of non-renewable natural aggregates like moraines and commercial insulating materials such as bentonite mats and geomembranes. When the local materials are utilized, it is important to consider the realistic availability of the materials, cost-effective distance of the material transportations and forming waste material amounts as the mining areas are large and the needed material amounts are very voluminous.
Preliminary results
Materials studies of the UPACMIC project show that by mixing ash with moraine, the water permeability value can be decreased. This allows in many cases the use of such local moraines that otherwise would not fill the requirements set for the protective structures.
The achieved water permeability level varies significantly depending on the initial materials and refining method, but according to the studies there are functional solutions to many mining sites that need protective structures.
According to the preliminary results there are evidences that by suitable (reactive) layer it is possible to impact on the amount and quality of the seepage water insomuch that it influences on the solubility behavior of the masses deposited in the enrichment sand. In this respect the studies are yet unfinished.
Interaction and chemical compatibility with other materials and structures , New products, applications and machinery , Processing possibilities and logistics
